Why do you charge per serving anyway, just set a starting price for 1 tier, 2, 3 etc cakes and increase it according to the difficulty of design and amount of work, then just tell people approximate number of servings they will get. That’s how I price my cakes and never had a problem. It’s their problem how many people they want to feed, if they want a 2 tier cake – they pay for 2 tiers. People pay for your time spent on the cake , ingredients are not expensive, so the price must depend on the design and time needed to accomplish. You are an artist not a baker if you make custom decorated cakes and you must charge accordingly. I hope this is helpful to you :)
